[Tests] update webpack resolver unit tests to check module resolution

Author: MustafaHaddara

resolvers/webpack/test/package-mains/module-and-jsnext/package.json

@@ -0,0 +1,5 @@
+{
+  "main": "lib/index.js",
+  "module": "src/index.js",
+  "jsnext:main": "lib/index.js"
+}

resolvers/webpack/test/package-mains/module-and-jsnext/src/index.js

@@ -21,6 +21,11 @@ describe('packageMains', function () {
       .to.equal(path.join(__dirname, 'package-mains', 'jsnext', 'src', 'index.js'));
   });
 
+  it('captures module instead of jsnext', function () {
+    expect(webpack.resolve('./module-and-jsnext', file)).property('path')
+      .to.equal(path.join(__dirname, 'package-mains', 'module-and-jsnext', 'src', 'index.js'));
+  });
+
   it('captures webpack', function () {
     expect(webpack.resolve('./webpack', file)).property('path')
       .to.equal(path.join(__dirname, 'package-mains', 'webpack', 'webpack.js'));